A page action is an icon that your extension adds inside the browser's URL bar.

Your extension may optionally also supply an associated popup whose content is specified using HTML, CSS, and JavaScript.

If you supply a popup, then the popup is opened when the user clicks the icon, and your JavaScript running in the popup can handle the user's interaction with it. If you don't supply a popup, then a click event is dispatched to your extension's background scripts when the user clicks the icon.

You can also create and manipulate page actions programmatically using the pageAction API.

Page actions are like browser actions, except that they are associated with particular web pages rather than with the browser as a whole. If an action is only relevant on certain pages, then you should use a page action and display it only on relevant pages. If an action is relevant to all pages or to the browser itself, use a browser action.

While browser actions are displayed by default, page actions are hidden by default. They can be shown for a particular tab by calling pageAction.show(), passing in the tab's ID. You can also change this default behavior using the show_matches property.

Syntax

The page_action key is an object that may have any of three properties, all optional:

Use this to include a stylesheet in your popup that will make it look consistent with the browser's UI and with other extensions that use the browser_style property. Although this key defaults to false, it's recommended that you include it and set it to true in order to make your popups consistent with the look of the rest of the browser user interface.

In Firefox, the stylesheet can be seen at chrome://browser/content/extension.css, or chrome://browser/content/extension-mac.css on OS X.

The Firefox Style Guide describes the classes you can apply to elements in the popup in order to get particular styles.

It's recommended that you supply two icons here, one 19x19 pixels, and one 38x38 pixels, and specify them in an object with properties named "19" and "38", like this:

"default_icon": {
"19": "geo-19.png",
"38": "geo-38.png"
}

If you do this, then the browser will pick the right size icon for the screen's pixel density.

You can just supply a string here:

"default_icon": "geo.png"

If you do this, then the icon will be scaled to fit the toolbar, and may appear blurry.

default_popup

String

The path to an HTML file containing the specification of the popup.

The HTML file may include CSS and JavaScript files using <link> and <script> elements, just like a normal web page. However, don't use <script> with embedded code, because you'll get a Content Violation Policy error. Instead, <script> must use the src attribute to load a separate script file.

Unlike a normal web page, JavaScript running in the popup can access all the WebExtension APIs (subject, of course, to the extension having the appropriate permissions).

Hide the page action by default for pages whose URLs match any of the given match patterns.

Note that page actions are always hidden by default unless show_matches is given. Therefore it only makes sense to include this property if show_matches is also given, and in this case it will override the patterns in show_matches. For example, consider a value like: